Twain Harte Valley Mwc
EPA ID: CA5500080 · 202 people served · 2 ZIP codes
Unlike many utilities its size, Twain Harte Valley Mwc carries a violation-free five-year record — no EPA notices, no MCL exceedances, serving 202 people.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Twain Harte Valley Mwc Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Twain Harte Valley Mwc serves a community with a median household income of $97,159 and an estimated 4,470 residents across its service area. Approximately 78% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
🌊 Where Does Your Water Come From?
Twain Harte Valley Mwc's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 1% of homes in Tuolumne County, California rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in California
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Twain Harte Valley Mwc (EPA ID: CA5500080) is a community water system in California that serves approximately 202 people from surface water sources.
This system provides water to 2 ZIP codes across 2 communities.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by CA or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Twain Harte Valley Mwc (CA5500080) on EPA.gov.
Frequently Asked Questions
Is Twain Harte Valley Mwc water safe to drink?
Based on EPA records, Twain Harte Valley Mwc has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Twain Harte Valley Mwc serve?
Twain Harte Valley Mwc serves approximately 202 people across 2 ZIP codes in California.
Where does Twain Harte Valley Mwc get its water?
The primary water source is surface water.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.